To reduce the city's carbon emissions, the mayor proposes replacing all gas-powered municipal vehicles with electric ones. This initiative will significantly improve air quality in the city. Which of the following is an assumption on which the mayor's argument depends?

✓ Correct Answer: Option A

The argument assumes that replacing gas vehicles with electric ones will reduce carbon emissions. This holds true only if the electricity itself is generated from non-carbon-intensive sources; otherwise, emissions could merely shift from tailpipes to power plants, undermining the conclusion.